GC Determination of Residual Amount of N-Methylimidazole in Ionic Liquid Intermediates

Residual amount of N-methylimidazole in ionic liquid intermediates was determined by GC with nitrogen-phosphorus detector (NPD).N,N-dimethylaniline was used as internal standard.The sample solution was separated on DB-FFAP capillary column (30 m×0.32 mm,0.25 μm).Linear relationship between values of peak area and mass concentration of N-methylimidazole was obtained in the range of 0.02-0.140 g·L-1,with values of limit of detection (3S/N) and lower limit of determination (10S/N) of 6.52 mg·L-1 and 21.73 mg·L-1,respectively.Test for recovery was made at two concentration levels,giving results of 96.4% and 96.2%.Value of RSD (n=5) found from the analytical results was 0.88%.